A catalytic converter is a device that catalyzes chemical reactions in which a combustion by-product or emission substance (such as CO, NOx, or the like) is converted to a more environmentally-friendly or less undesirable substance (such as CO2, H2O, N2, or the like). Catalytic converters are commonly used for emission control by providing a catalyst environment (typically without consumable chemicals) to treat exhaust gases from, e.g., internal combustion engines, air conditioning systems, or the like. Typically, a catalytic converter includes a disk or block-shaped catalyst element mounted in a housing, and is placed in the exhaust path of an emission producing system or machine. It is desirable that the catalyst element is readily replaceable. It is also desirable to form a leak-proof seal between the catalyst element and the housing wall so that all the exhaust gas will go through the catalyst element to maximize conversion. In conventional catalytic converters, different fixture assemblies have been used to secure the catalyst element in position. However, these fixture assemblies suffer some drawbacks. For instance, in conventional catalytic converters, one cannot conveniently adjust the pressure applied to the catalyst element for securing it in position and forming a tight seal. Some of them do not apply sufficient pressure to form a stable tight seal; others have complicated structures and are inconvenient to use. They are also not adjustable to accommodate catalyst element size variations. In some conventional catalytic converters, the seal between the catalyst core and the housing is tight but catalyst core is fixedly mounted in the housing and therefore is not removable for maintenance or replacement.
Accordingly, there is a need for a catalytic converter that overcomes one or more of these shortcomings.